Abstract

In March 2005, a sudden mudslide involving some 10,000 m3 of material took place west of the Antsirabe basin in the highlands of Madagascar. The slope failure caused material damage to terraced rice fields, and due to its close proximity to a town (Antsirabe) generated considerable media interest. The flow seems to have occurred following 10 days of accumulated rainfall of high frequency. However, the total precipitation (271 mm) was not exceptional (20-year return frequency). The slope failure, as elsewhere, appears to have been triggered in relation to a combination of morphopedological, climatic and possibly seismic factors that operated on different time scales. It is believed that this is the first time such an event has been described from this environment.